add-discriminators: Fix handling of lexical scopes.

This fixes a bug in the handling of lexical scopes, when more than one
scope is defined on the same line or functions are inlined into call
sites that are on the same line as the function definition. This
situation can easily happen in macro expansions.

The problem is solved by introducing a SmallDenseMap<DIScope *,
DILexicalBlockFile *, 1> that keeps track of all the different lexical
scopes that share a line/file location.

Fixes PR30681.

llvm-svn: 284998

2 files changed, 92 insertions, 4 deletions

diff --git a/llvm/test/Transforms/AddDiscriminators/inlined.ll b/llvm/test/Transforms/AddDiscriminators/inlined.ll
new file mode 100644
index 00000000000..25bbd54dfb5
--- /dev/null
+++ b/llvm/test/Transforms/AddDiscriminators/inlined.ll
@@ -0,0 +1,85 @@
+; RUN: opt < %s -add-discriminators -S | FileCheck %s
+;
+; Generated at -O3 from:
+; g();f(){for(;;){g();}}g(){__builtin___memset_chk(0,0,0,__builtin_object_size(1,0));}
+; The fact that everything is on one line is significant!
+;
+; This test ensures that inline info isn't dropped even if the call site and the
+; inlined function are defined on the same line.
+source_filename = "t.c"
+target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+target triple = "arm64-apple-ios"
+
+; Function Attrs: noreturn nounwind ssp
+define i32 @f() local_unnamed_addr #0 !dbg !7 {
+entry:
+  %0 = tail call i64 @llvm.objectsize.i64.p0i8(i8* inttoptr (i64 1 to i8*), i1 false) #2, !dbg !11
+  br label %for.cond, !dbg !18
+
+for.cond:                                         ; preds = %for.cond, %entry
+  ; CHECK: %call.i
+  %call.i = tail call i8* @__memset_chk(i8* null, i32 0, i64 0, i64 %0) #2, !dbg !19 
+  ; CHECK: br label %for.cond, !dbg ![[BR:[0-9]+]]
+  br label %for.cond, !dbg !20, !llvm.loop !21
+}
+
+; Function Attrs: nounwind ssp
+define i32 @g() local_unnamed_addr #1 !dbg !12 {
+entry:
+  %0 = tail call i64 @llvm.objectsize.i64.p0i8(i8* inttoptr (i64 1 to i8*), i1 false), !dbg !22
+  %call = tail call i8* @__memset_chk(i8* null, i32 0, i64 0, i64 %0) #2, !dbg !23
+  ret i32 undef, !dbg !24
+}
+
+; Function Attrs: nounwind
+declare i8* @__memset_chk(i8*, i32, i64, i64) local_unnamed_addr #2
+
+; Function Attrs: nounwind readnone
+declare i64 @llvm.objectsize.i64.p0i8(i8*, i1) #3
+
+attributes #0 = { noreturn nounwind ssp }
+attributes #1 = { nounwind ssp  }
+attributes #2 = { nounwind }
+attributes #3 = { nounwind readnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM version 4.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "t.c", directory: "/")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"PIC Level", i32 2}
+!6 = !{!"LLVM version 4.0.0"}
+; CHECK: ![[F:.*]] = distinct !DISubprogram(name: "f",
+!7 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, variables: !2)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10}
+!10 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!11 = !DILocation(line: 1, column: 56, scope: !12, inlinedAt: !13)
+!12 = distinct !DISubprogram(name: "g", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, variables: !2)
+!13 = distinct !DILocation(line: 1, column: 17, scope: !14)
+; CHECK: ![[BF:.*]] = !DILexicalBlockFile(scope: ![[LB1:[0-9]+]],
+; CHECK-SAME:                             discriminator: 1)
+!14 = !DILexicalBlockFile(scope: !15, file: !1, discriminator: 1)
+; CHECK: ![[LB1]] = distinct !DILexicalBlock(scope: ![[LB2:[0-9]+]],
+; CHECK-SAME:                                line: 1, column: 16)
+!15 = distinct !DILexicalBlock(scope: !16, file: !1, line: 1, column: 16)
+; CHECK: ![[LB2]] = distinct !DILexicalBlock(scope: ![[LB3:[0-9]+]],
+; CHECK-SAME:                                line: 1, column: 9)
+!16 = distinct !DILexicalBlock(scope: !17, file: !1, line: 1, column: 9)
+; CHECK: ![[LB3]] = distinct !DILexicalBlock(scope: ![[F]],
+; CHECK-SAME:                                line: 1, column: 9)
+!17 = distinct !DILexicalBlock(scope: !7, file: !1, line: 1, column: 9)
+!18 = !DILocation(line: 1, column: 9, scope: !7)
+!19 = !DILocation(line: 1, column: 27, scope: !12, inlinedAt: !13)
+; CHECK: ![[BR]] =  !DILocation(line: 1, column: 9, scope: ![[BF2:[0-9]+]])
+; CHECK: ![[BF2]] = !DILexicalBlockFile(scope: ![[BF]],
+; CHECK-SAME:                           discriminator: 1)
+!20 = !DILocation(line: 1, column: 9, scope: !14)
+!21 = distinct !{!21, !18}
+!22 = !DILocation(line: 1, column: 56, scope: !12)
+!23 = !DILocation(line: 1, column: 27, scope: !12)
+!24 = !DILocation(line: 1, column: 84, scope: !12)
diff --git a/llvm/test/Transforms/AddDiscriminators/oneline.ll b/llvm/test/Transforms/AddDiscriminators/oneline.ll
index 72d7a6eadbf..aa52ae42ee4 100644
--- a/llvm/test/Transforms/AddDiscriminators/oneline.ll
+++ b/llvm/test/Transforms/AddDiscriminators/oneline.ll
@@ -88,11 +88,14 @@ attributes #1 = { nounwind readnone }
 !27 = !DILocation(line: 2, column: 42, scope: !20)
 !28 = !DILocation(line: 3, column: 1, scope: !4)
 
+; CHECK: ![[F:.*]] = distinct !DISubprogram(name: "foo",
+; CHECK: ![[IF:.*]] = distinct !DILexicalBlock(scope: ![[F]],{{.*}}line: 2, column: 7)
 ; CHECK: ![[THEN1]] = !DILocation(line: 2, column: 17, scope: ![[THENBLOCK:[0-9]+]])
-; CHECK: ![[THENBLOCK]] = !DILexicalBlockFile({{.*}} discriminator: 1)
+; CHECK: ![[THENBLOCK]] = !DILexicalBlockFile(scope: ![[IF]],{{.*}} discriminator: 1)
 ; CHECK: ![[THEN2]] = !DILocation(line: 2, column: 19, scope: ![[THENBLOCK]])
-; CHECK: ![[THEN3]] = !DILocation(line: 2, column: 7, scope: ![[THENBLOCK]])
+; CHECK: ![[THEN3]] = !DILocation(line: 2, column: 7, scope: ![[BRBLOCK:[0-9]+]])
+; CHECK: ![[BRBLOCK]] = !DILexicalBlockFile(scope: ![[F]],{{.*}} discriminator: 1)
 ; CHECK: ![[ELSE]] = !DILocation(line: 2, column: 25, scope: ![[ELSEBLOCK:[0-9]+]])
-; CHECK: ![[ELSEBLOCK]] = !DILexicalBlockFile({{.*}} discriminator: 2)
+; CHECK: ![[ELSEBLOCK]] = !DILexicalBlockFile(scope: ![[IF]],{{.*}} discriminator: 2)
 ; CHECK: ![[COMBINE]] = !DILocation(line: 2, column: 42, scope: ![[COMBINEBLOCK:[0-9]+]])
-; CHECK: ![[COMBINEBLOCK]] = !DILexicalBlockFile({{.*}} discriminator: 3)
+; CHECK: ![[COMBINEBLOCK]] = !DILexicalBlockFile(scope: ![[IF]],{{.*}} discriminator: 3)